Epidemiologic investigations on brain tumors in the GDR: possibilities and limits.

Animal experiments and recent industrial medicine investigations suggest that chemical carcinogens in the environment could be responsible for some types of human brain tumors. Confirmation demands data on the epidemiology of human tumors of a precision which has been unavailable. Prerequisites for valid epidemiologic studies are presented and the current situation in the GDR is critically evaluated in that context. The conditions for such studies are met fully only in early childhood. Based on files of the National Cancer Registry of the GDR, 1960-1979, 55 children with histopathologically confirmed tumors of the central nervous system prior to the end of the first year of life have been identified. The overall frequency was 1.1 per 100,000 births. Males were affected more than twice as often as females. Incidence for the years 1970-1979 was significantly higher than for 1960-1969. Possible explanations are critically explored and it is concluded that further epidemiologic studies of brain tumor etiology in early life must also consider children with onset of tumor symptoms during the first year of life but in whom histological confirmation was secured thereafter.